The subject matter of this invention is a dental handpiece having provision for swiveling about its axis, illumination of its work area, and the delivery of water and air to the work area.
The most relevant prior art that I know of is the AM-40 handpiece manufactured and sold by the Ritter-Midwest division of Sybron Corporation, the assignee of the present invention. The AM-40 handpiece is illustrated and described in advertising literature entitled The AM-40 Multi-Speed System accompanying this application. A brief reference to this accompanying literature, in particular the diagram of the handpiece described therein, will serve as convenient background to the present invention. The handpiece is shown there as having two major components: a handpiece motor shown in gray and a handpiece attachment shown only in outline and attached to the motor. The male connector portion of the motor fits within the attachment and is sealed relative to the attachment by three O-rings which define a pair of annular flow channels, one for chip air and one for water. The attachment is swivelable relative to the motor and the annular channels permit the continuous flow of chip air and water from the motor casing to the attachment regardless of angular displacement or swiveling of the attachment.
To this prior art, the present invention adds provision for light transmission to the work area. This is accomplished by means of electrical energy delivered to an annular commutator disposed on the motor housing at the swivel interface between motor housing and handpiece attachment. The handpiece attachment in turn includes an electric lamp with a removable base in sliding contact with the commutator. The lamp illuminates an optical fiber bundle which extends from the lamp to the head end of the attachment for illumination of the work area.